It would connect turbines off the wind-lashed north coast of Scotland with Germany's vast arrays of solar panels, and join the power of waves crashing on to the Belgian and Danish coasts with the hydro-electric dams nestled in Norway's fjords: Europe's first electricity grid dedicated to renewable power will become a political reality this month, as nine countries formally draw up plans to link their clean energy projects around the North Sea.

The network, made up of thousands of kilometres of highly efficient undersea cables that could cost up to €30bn (£26.5bn), would solve one of the biggest criticisms faced by renewable power – that unpredictable weather means it is unreliable.